I've not been able to startup my MacBook Pro. I made a backup of Mountain Lion using Lion DiskMaker 2.0.2. When I press option and the power button then select the USB drive, the grey screen with the apple logo and spinner appears then shortly after I get a solid royal blue screen. Is there anyway I can boot from the USB drive backup to fix my computer?
MacOS – Blue screen when booting from USB backup of Mountain Lion
macbook promacosstartup
Related Solutions
This suggestion seems to helps a lot with all sorts of things, so I figured I'd suggest it here just in case.
Go to your Disk Utility app and press the following buttons in the numbered order. I would recommend only doing 1, 2, and 3, but if this doesn't help with the problem, you can also try to run 1(b) from Recovery Mode (or while running your computer off an external hard drive) because it won't work while you're logged on.
Hope this helps :)
A typical issue causing long boot times is a faulty or missing selection of the startup disk. Go to System preferences > Startup Disk and make sure your Startup Volume is selected there.
Another thing which definetly helps to improve startup times on my MBP is running Onyx from time to time and have it rebuilt system caches, etc. (see tab "Automation"). Make sure to backup first.
Related Question
- MacOS – Downgrading from OS X Mountain Lion to Snow Leopard gets stuck at Apple logo
- MacOS – Macbook Pro boots successfully when using hard drive in USB enclosure but doesn’t boot when connected internally
- MacOS – MacBook Pro can’t boot: shows Apple logo then grey screen
- MacOS – How to install Mountain Lion on USB disk and boot from USB
- MacOS – Cannot boot from usb
- MacBook – Grey screen when booting from original disk, doing Internet recovery or booting from High Sierra boot disk
- MacOS – Macpro 5,1 mid 2010 cannot boot to Mojave from Mountain Lion
Best Answer
Lion Disk Maker is a third-party utility. It’s likely that updates to OS X changed the startup behavior slightly for how your machine operates.
Any reason you wouldn’t use Recovery Disk? (Command + R on boot.)
You can also try booting to the USB drive, but enable verbose mode (before you select the USB drive, hold down Command + V) to see if there are particular errors shown when it is at that blue screen.
Last bit of hope: the author appears receptive to personal technical support questions by e-mail (that’s pretty cool).